In its current form no. It requires all new purchases to be registered (well, all those done through an FFL. C&R to C&R, just like FFL to FFL doesn't appear to require registration. And of course Criminals purchasing guns illegal don't need to register per Haynes vs US. Only non-criminals can be required to register guns. I mean, seriously, WHAT. THE. F. https://en.wikipedia.org/wiki/Haynes_v._United_States . No I wouldn't expect criminals to comply, but the fact that they literally can't be charged with a crime for failing to register, but an otherwise law abiding citizen CAN be charged is beyond the pale)
However, if you are an out of state resident and establish residency in Maryland, as per handguns, all of your long guns must be registered. I think it is a $10 or $20 fee (for all guns, not per gun). Then you have to provide a description, make and model, serial number, your DL# or SONDEX#, name, address, date of birth, hair and eye color, ethnicity, weight, height, a sperm or egg sample, 4 written letters of recommendation and please no stool samples.
I may have been slightly exaggerating on the last 3. However, all the rest is required.
So, if you decide not to register, what is the penalty?