Md. Code, Commercial Law § 9-310

(a) Except as otherwise provided in subsection (b) and § 9-312(b), a financing statement must be filed to perfect all security interests and agricultural liens.

(b) The filing of a financing statement is not necessary to perfect a security interest:

(1) That is perfected under § 9-308(d), (e), (f), or (g);

(2) That is perfected under § 9-309 when it attaches;

(3) In property subject to a statute, regulation, or treaty described in § 9-311(a);

(4) In goods in possession of a bailee which is perfected under § 9-312(d)(1) or (2);

(5) In certificated securities, documents, goods, or instruments which is perfected without filing, control, or possession under § 9-312(e), (f), or (g);

(6) In collateral in the secured party’s possession under § 9-313;

(7) In a certificated security which is perfected by delivery of the security certificate to the secured party under § 9-313;

(8) In deposit accounts, electronic chattel paper, electronic documents, investment property, or letter-of-credit rights which is perfected by control under § 9-314;

(9) In proceeds which is perfected under § 9-315; or

(10) That is perfected under § 9-316.

(c) If a secured party assigns a perfected security interest or agricultural lien, a filing under this article is not required to continue the perfected status of the security interest against creditors of and transferees from the original debtor.