I have a created character i would like to turn into an npc for my current campaign. Is it possible to get him “selectable” in the encounter building feature. Thx

I would love this.

or the ability  to convert a PC to homebrew monster

I also would like this.  Rather than rummage through notes to remember what NPCs are where, have them "stuck" to the place/encounter where the characters met them.

OMG, this needs to be a thing!

In my opinion, I think it is better to just improve homebrew to make it as intuitive to use as the character builder rather than wasting resources making a tool to convert PCs to monsters. The only reason to use the character builder for NPCs is due to ease of use. However, if a person wants to make NPCs on a frequent basis, I think they are better served by spending some time to learn to use the homebrew tools and create an NPC directly rather than doing it in a roundabout way through the character builder.

There's a homebrew NPC creator?  

Quote from MJC >>

There's a homebrew NPC creator?  

NPCs are monsters, so they use the same creator as monsters.

You all might want to chime in on the feedback portal for the encounter builder/combat tracker: https://www.dndbeyond.com/forums/d-d-beyond-general/d-d-beyond-feedback/encounters-feedback-portal/114888-encounters-feedback

Hmm.  I'm old so I am trying to wrap my head around this.  How can I create, say...a human necromancer (wizard) as a monster?  I am not seeing human or wizard or necromancer as a  monster in the list.  Would I just have to create that from scratch?  Would that work similarly for creating a barkeep, stable boy, or whatever?

I've been using DNDBeyond for a couple of years now but have only started to play around with encounter building.  When I say I'm old, I mean I started playiong D&D when we used these wooden sticks filled with graphite, and sheets of pressed wood pulp to keep track of everything.  In those days NPCs were not, at all, the same as monsters so this is bit of a new concept to me. 

I'm being a little tongue in cheek, but I'm also kind of serious right now.  I'm not accustomed to NPCs being treated as monsters and am trying to figure out how to create NPCs in the monster builder.  My human necromancer is a very specific example for a reason; he is my villian/boss, and I wanted to try to create an encounter with him in the encounter builder.  Any tips on how to do this would be greatly appreciated.  

Necromancer and other schools of wizard stat blocks are from Volo's Guide to Monsters. If you have not purchased VGTM, there is not an easy way to copy and homebrew it.

However, the archmage is from the Basic Rules so it should be free, and you can just copy and homebrew that stat block and then adjust the CR, spells, and stats to your liking, so there is no need to homebrew the entire thing from scratch.

5e is the first edition I played, so I am not sure how older editions handle NPCs. In this edition, NPCs and monsters use the same stat blocks to make running the game easier. As a GM, I could technically run monsters using character sheets, but it is a hassle and I honestly do not need that level of detail for most of my monsters. While my players are each playing an RPG controlling one character, I as a GM am playing an SRPG controlling multiple monsters, sometimes several different kinds at the same time, and occasionally even playing monsters both on the player's side and on the enemy's side. I do not want to be digging through all the extra tabs to find abilities I want to use, and I should not even give each of my monsters two dozen unique abilities in the first place either. When I do homebrew for monsters, those monsters are usually significant bosses or sidekicks, and I will give them more abilities than usual, but they are still nowhere near as complex as the PCs around their level, and their abilities are usually simple stuff like having lots of immunities, having advantage on all attack roles, having infinite reactions, or something along those lines.

For spell casters as the big villain, I recommend eschewing spell slots altogether (so there is less things to keep track of) and let the spell caster cast whatever spell you need, at whatever level you want, and at whatever frequency you want. However, I still recommend putting several common spells that you think you will cast a lot on the stat block itself so you do not have to dig through the database.

Thanks, this is a huge help.  I do not own VGtM but I am certainly not opposed to purchasing the specific content that will help me create my NPC(s), so I will do that.

I'm an AD&D (1E & 2E) guy and those rules weren't as detailed as 5E.  NPCs and PCs had character sheets.  We used 3X5 cards to create stat blocks for monsters, NPCs and PCs and laid them out behind the DM screen (usually a 3 rinbg binder).  We also walked up hill, in the snow to all of our game sessions...both ways...with no shoes.  ;)

Anyway, thanks for the explanation and the pointers to the stat blocks I need.  I apologize for derailing this thread; hopefully this helps others as it helped me.