D&D 5E Modern

There is no official D&D5E Modern like there was for 3/3.5. D20 Modern will always be one of my favorites in spite of its flaws.

There are some pretty neat 3rd party 5E Modern products out there, however.

Here are some of them at this time.

Ultramodern5

The mission of U5 is to present 5th EDITION rules for use in non-fantasy settings. These include pre-modern settings, contemporary settings, and those that are far flung fantastic and futuristic. U5 presents modern and science fiction rules in a game usually reserved for fantasy. There is no established setting in U5.
It presents classes, gear, and scenarios that can be inserted into any campaign, including the following:

• Cyberpunk
• Espionage
• Modern Warfare
• Space Opera
• Techno Fantasy
• Urban Fantasy
• Steampunk
• Wild West (with or without aliens)

You may explore the rules in whatever context you wish. Rules are generalized, encouraging homebrew settings and the rebranding of elements.
Create a pure science fiction setting, or insert these rules into your own fantasy world to offer a unique spin. 

THIS SOURCEBOOK INCLUDES:

• A revised “ladder” system, offering more adjustability with character creation. Modify your class with one of seven ladders.
• Revamped rules around being human.
• A new lifepath system incorporating backgrounds (with eleven new ones) into an adjustable life history where characters can select every aspect of their character’s history, from family and friends to past love affairs.
• Ten new classes including the infiltrator, medic, sniper, and techie.
• Twenty-four archetypes
• All new weapons including traditional firearms, rocket launchers, and laser rifles
• New armor including powered combat suits.
• Purchase and modify vehicles
• Over forty new monsters including giant robots.
• Two included adventures—a zombie apocalypse and an alien invasion.

Ultramodern5 is aailable on DriveThruRPG where it is available in soft or hard cover print.

Ultramodern5 does have a plug-in expansion product called APEX.

History once spoke of individuals able to accomplish miracles, eventually eradicated or bred out by a population too frightened of what they didn't understand. As science filled in the void left by absent gods, these gifted individual decreased until they became all but extinct. But they never completely vanished. Each generation, such a rare being appeared with abilities subtle to extreme. However, despite their desire to reveal themselves, forces continually prevent them from doing so.
To many of those who know them, they're of an inferior class. To others, including themselves, they are considered an improvement on the design of man, an upper echelon.
The apex. 

Apex is a module for DEM's Ultramodern5, a plug-in rather than a full setting: a set of rules and ideas to allow any number of homebrew settings to work within it. There is a basic background involving people who gain unnatural powers, but don't let that limit you if you wish to use it as a jumping off point.
Apex includes the following:

--Tier-based talent acquisition. Over 180 upgradable super-powered talents, totalling over 950 different variations.
--New sacrifice rules to trade penalties for new talents.
--Eleven new backgrounds and apex-themed life events.
--Eleven new ladders to focus your superpowers.
--New adversary templates and monsters.

APEX available at DriveThruRPG

Hyperlanes

Hyperlanes takes 5E to the sci-fi genre.

Adventure at hyperspeed, smirking at the authorities along the way. Tramp around a hostile galaxy in a starship held together with spit and pluck. You’re a motley crew of misfits, gathered by chance, venting your frustrations through witty barbs and alien howls.
Strap in, kid. We’re gunna burn across the sky ‘til the stars become lines.
HYPERLANES is the gaming technology that takes you there. We begin with all new Classes and Archetypes, reverse engineered from the basic building blocks of the D&D Player’s Handbook, but reprogrammed for scifi adventuring among the stars, integrating starship battle abilities from the ground up. We splice in all new Feats for cinematic action, systems for building alien species and robot chassis as Races, and iconic Backgrounds to add dimensionality to your spacer.  

We don’t stop there.
We hook up a hard hitting chapter on armor clad soldiers, fringe-planet crime lords, and monstrous alien threats. We install a honed system for enabling memorable space battles, designed to send a chill up your spine as you blast hostile spacecraft out of the starry sky. We bury you in “magical items” recast as scientific marvels and scavenged technology from forgotten civilizations.  

HYPERLANES is a humming engine of science fiction action and it’s what you need to adapt your favorite star spanning adventure setting to your living room cockpit. We take inspiration from such classics as Star Wars, Firefly, Cowboy Bebop, and Guardians of the Galaxy. We’re pretty sure this is the action scifi supplement you’ve been looking for.
This book was Kickstarted in December 2016 and we are happy to report that it successfully funded at over $40,000. Stretch goals from such an amazing total allowed us to hire on additional writers and artists and really make this book something memorable.

Hyperlanes available at DriveThruRPG

There are even some adventures published for this setting.

The Celadon Caravan is an extended adventure for HYPERLANES for characters of 1st-5th level. It's a story in three acts, with action at every turn as the characters struggle to save a fleet of ships under attack by mysterious forces. Bending time and space, this adventure shows off the HYPERLANES Gambit system in all its glory and introduces players to vehicles battles. There's even a chance to rebuild a ruined starship, waiting for a crew.

Hyperlanes: The Celadon Caravan available at DriveThruRPG

The HYPERLANES Unfolding Starscapes is a guide to blending fantasy with science fiction. Covering conversions, science-fantasy, and middle ground topics like psionics, the supplement is a greatly anticipated addition to the HYPERLANES collection.

Hyperlanes: Unfolding Starscapes available at DriveThruRPG

Hellscapes expands the Hyperlanes line into post apocalyptic genres.

Living is hard, now that society has fallen. We used to complain that our lives were boring. These days, every moment is a struggle. Every meal is earned. Every breath is precious. Dangers roam the landscape, both human and worse. Few survive, and numbers dwindle. Those who manage to live long are legend, hardened heroes or monstrous villains. You are among them.

Your canteen, your weapon, your food: these are the most precious treasures in the world. But once you reach our level you might start wanting more, the whispered wonders yet to be uncovered. Secrets of old ready to come back into the harsh light of this fallen world.  

Will you plumb those depths and scour the wastelands for what we’ve lost? Will you band together with fellow survivors, watching each other’s backs in the treacherous night? Will you lend a blistered hand to rebuilding society in this hell of a world? Or will you break what is left of it, and remake it anew? 

HELLSCAPES is the beaten and battered manual you need to run post-apocalyptic survival games. We’ve scavenged the noble bones of Dungeons & Dragons 5th edition, reworking its lightweight materials into twisted mechanics to serve our needs. We bastardize classes into those that suit the wastes, allowing for new and dangerous heroes to arise. We’ve repurposed the raw materials of Feats and Backgrounds to reflect the storylines of hardened scavengers. We recast Races into Origins, allowing you to customize tribes, mutations, and robotic enhancements to suit the hellish campaign settings you choose.  

Need a game where society collapses as the dead rise to consume the living? Want to see how you’d fare against the unblinking gaze of robotic overlords? Hope to lead the uprising of a human resistance against alien conquerors? We’ve got the system for you.  

HELLSCAPES includes all the post-apocalyptic baddies your DM needs to tear you limb from limb, leaving more food for those who remain. Just kidding, we’re sure you’ll make it tough guy.  

We’re building HELLSCAPES on the engine that drives our last Kickstarter, the highly successful HYPERLANES. There we showed that magical spells could be converted into a system of gambits, where skill and pluck can easily play out as powerful but limited abilities. Here we go further, inventing hundreds of new Gambits for deployment against barbaric raiders and hostile environments alike.  

Built lightweight and simple, gambits allow for creative uses beyond our own limited imaginings. This is where players flourish, bending raw Gambits to the needs of the moment in bursts of creativity.  

We’ve even made sure to include Gambits for use in daring vehicular chases. If you want hellish landscapes traversed by spike-mounted dune buggies and cargo trucks, we’ve got you covered. Since HYPERLANES was made to handle space flight, we’ve got this vehicles thing down pat. HELLSCAPES is all about action movie stunts and gasoline explosions.

Hellscapes available at DriveThruRPG

Fifth Age

It is the dawn of the 24th century, and an interesting point in time for the human race. Fifth Age chronicles the dawn (perhaps more like early mid-morning) of humanity exploring the stars and getting into all manner of trouble, fraught with peril, excitement and drama. The science in this sci-fi is a little on the harder side than some might be used to and the adventure is a little pulpy, a perfect mix for the 5e DnD system.

• New Races
• New Classes
• New and expanded backgrounds (with mechanical relevance!)
• New Skills
• New Feats (along with rebalancing)
• New Weapons
• New Armor
• Hi-Tech Gadgets
• Downtime Shenanigans
• Investments, Trading and Retirement Rules (Contribute to your retirement fund, or wind up eating catfood!)
• Spaceship Rules

This product is a work in progress and free. All of the relevant files can be found here...

Fifth Age files link